Power bending machine and control means therefor



March 11, 1969 P. c. NELSON ETAL 3,431,753

POWER BENDING MACHINE AND CONTROL MEANS THEREFOR Filed April 4, 1967 I of Sheet W o 5 M A 5 l a Z March 11, 1969 p, c, NELSON ET L 3,431,758

POWER BENDING MACHINE AND CONTROL MEANS THEREFOR Sheet 2 of 5 Filed April 4, 1967 w wnm March 11, 1969 P. c. NELSON ETAL 3,431,758

POWER BEND ING MACHINE AND CONTROL MEANS THEREFOR Filed April 4, 1967 Sheet 3 of 3 (8% Z Twin/always United States Patent 22 Claims ABSTRACT OF THE DISCLOSURE A power bending machine has its bending pin-mounting plate spindle directly driven reversibly by a rotary actuator hydraulic motor controlled by a manual lever through a link to rock a cross arm of a directional selector carrying trip dogs which responsively motivate a two-arm bell crank to open a normally closed control valve in the hydraulic supply circuit. A calibration index and an abutment are driven by the motor. Respective adjustable stops on a reciprocably and rotatably indexibly mounted gage bar are engageable by the abutment to shift the bar and actuate a link to rock a tripper which disengages the operational dog from the bell crank for deactivating the selector, closing the control valve, and stopping the motor.

exemplary, driving means for a pressure-applying tool carrying member must be controlled in operation to drive the member in either of oposite working directions as well as in respective return or back-off directions. In such machine tools manual as well as automatic motor controls are desirable. Means should be provided whereby the machines can be quickly setup for experimental and production operation or runs, and which will facilitate accurate resetting of the machines for workpiece duplication.

Power benders have varied in angular velocity and torque for oposite direction of movement, and have had unduly complex and costly driving structures and control devices. Such benders have not been as easy or simple to adjust for various operational requirements as desirable, and have had other deficiencies and shortcomings which it is the aim of the present invention to overcome and to improve upon.

It is, accordingly, an important object of the present invention to provide a power bending machine having new and improved hydraulically operated driving means.

A further primary object of the present invention is to provide a power bender which will have the same output torque and/or output speed for either direction of movement.

Another object is to provide new and improved control means for a tool-driving hydraulic motor and which will overcome prior deficiencies and undesirable characteristics in a compact, efficient, easily adjusted, positively operating, minimum cost mechanism.

A further object of the invention is to provide a novel manually operable hydraulic machine tool motor controlling mechanism with automatic motor-responsive shutoff.

A yet further object of the invention is to provide an improved motor-operated trip mechanism for stopping a tool-driving hydraulic motor.

Still another object of the invention is to provide improved indexing means in a tool-driving hydraulic motor control apparatus.

Yet another object of the invention is to provide, in a hydraulic motor control aparatus, improved quickly adjustable gage bar means.

A still further object of the invention is to provide a novel selector device for a reversible hydraulic machine tool motor control apparatus.

It is also an object of this invention to provide power bending tool motor control means which are quickly selectively indexible for controlling repetitive actuations of the motor to produce difierent bends of varying respective degrees along lengths of stock.

Other objects, a features and advantages of the present invention will be readily apparent from the following detailed description of a preferred embodiment thereof taken in conjunction with the accompanying drawings, in which:

FIGURE 1 is a fragmentary front elevational view of -a power bender representative of a machine tool emtional detail view taken substantially along the line IIIIII of FIGURE 1;

FIGURE 4 is a fragmental sectional elevational detail view of the combination linearly movably mounted reciprocable indicator and abutment means of the device showing it in engagement with one of the stops on the stop bar;

FIGURE 5 is a fragmental longitudinal sectional plan view of the indexible stop bar of the control apparatus;

FIGURE 6 is a side elevational view of one of the adjustable stops of the apparatus;

FIGURE 7 is an enlarged fragmentary sectional isometric view taken substantially along the line VII-VH of FIGURE 5; and

FIGURE 8 is a fragmentary sectional elevational detail view taken substantially along the line VIII-VIII of FIGURE 1.

A power bender 10 (FIGS. 1 and 2,) comprises a work table area 11 at a suitable height on top of a cabinet 12 having a front wall 13. Mounted over the lefthand portion of the table 11 is a mounting disk or plate 14 which is supported corotatively on a vertical spindle 15 extending through the table 11 and oscillatable by means of a reversible rotary actuator type of hydraulic motor 17 (FIGS. 1 and 3) of which the wingshaft is at least functionally integral with the spindle to attain constant angular velocity and full bending torque power in each oscillatory direction. Bending of fiat, round, square and extruded metal stock is effected by inserting it betwen a center pin or mandrel 18 projecting above the plate 14 and a bending nose 19 mounted on the table 11 to project adjustably over the plate in suitable spaced relation to the mandrel, and then operating the motor 17 to drive the plate 14 rotatably either clockwise or counterclockwise to force an eccentrically mounted bending pin 20 spaced from the mandrel 18 bendingly against the workpiece.

The motor 17 comprises a housing suitably fixedly mounted within the cabinet 12 and defining therein 3. cylindrical working chamber 22 within which the spindle/ wingshaft 15 is coaxially oscillatable by hydraulic driving fluid alternately oppositely thrusting against a radial vane 23 coacting with a fixed abutment 24 to subdivide the Working chamber 22 into subchambers. Selective hydraulic pressurization of the subchambers is through conduits 25 by means of a constant volume pump 27 and with the other subchamber alternatively drained oil? to a sump 28, under the control of a valve 29. Desirably, the valve 29 comprises an annularly grooved spool normally held closed by respective opposite end biasing springs 30 3 and 31...A.stem .32 extends from one end .of the valve for selectively reciprocably shifting it to open the circuit for either clockwise or counterclockwise actuation of the spindle/wingshaft 15 and thereby the bender plate 14.

Improved means are provided for selectively opening the valve to connect the hydraulic circuit drivingly with the motor 17, herein comprising a selector 33 arranged to be actuated by means comprising a lever 34 conveniently in the form of a knobbed handle readily accessible for manipulation at a convenient height and desirably adjacent the right side of the front panel 13 having a vertical clearance slot 35 through which the handle extends inwardly. At its inner end, the handle lever 34 is fixedly secured to a motion transmitting disk 37 which is mounted on a horizontal pivotal axis alongside a supporting bracket block 38 therefor suitably attached inside the front wall panel 13 as by means of screws 39. Suitable means for pivotal mounting of the disk 37 on the bracket block 38 may include a bolt 40. Through this arrangement, control valve operation is adapted to be effected manually by selective rocking of the lever handle 34 to correspondingly rotate the transmission disk 37 to operate the selector 33.

For transmitting operating handle motion to the selector 33, a link 41 is pivotally connected to the transmission disk 37 to be reciprocated thereby. At its opposite end portion, the link 41 is pivotally connected to a control arm 42 fixedly attached to a shaft 43 rotatably mounted on a suitable supporting bracket 44. Oscillatory rocking of the shaft 43 causes corresponding rocking of a cross arm 45 which is fixedly secured to the shaft midway the length of the cross arm and provides one operating end of the selector 33. Rocking of the arm 45 relatively reciprocably motivates respective trip dog members 47 and 48 which are in the form of complementary, coextensive elongated thrust bars each having means such as a bolt 49 pivotally attaching it to one of the respective end portions of the rockable cross arm. At the opposite end of the selector 33, the trip dogs 47 and 48 have their respective ends separably coupled to a double arm bell crank member 50 which is freely rotatably mounted on a shaft 51 at least in part supported by the bracket 44 in spaced parallel relation to the cross arm shaft 43. Each of the opposite arms of the bell crank 50 has a bifurcation slot 52 into which the associated end of the respective trip dog extends in guided relation with a thrust pin 53 extending across the bifurcation and engaged within a reentrant notch 54 providing a thrust shoulder 55 facing longitudinally toward the thrust pin and a guide finger 57 extending slidably along the outer side of the thrust pin. Normally the trip dogs 48 are biased toward one another by means such as a tension spring 58 extending between and anchored at its opposite ends to the trip dog, whereby both of the trip dogs are normally in thrust connection with their respective arms of the bell crank 50. Thereby, when the handle lever 34 is rocked to effect corresponding rocking of the cross arm 45, the bell crank 50 is also correspondingly rocked about the shaft 51 by means of the respective trip dog thrust connections therewith.

Transmission of rocking movement of the bell crank 50 to the control valve 29 through its stem 32 is effected by means of a bifurcated third central arm 59 on the bell crank 50 which is connected to the stem 32 through a link 60. By virtue of its biasing springs 30 and 31, the valve 29 normally remains in the circuit closing position in respect to the hydraulic motor 17, and through its linkage and selector connection with the operating handle lever 34, maintains the handle in a neutral position from which it is adapted to be rocked for selectively opening the valve. According to the arrangement exemplified, outward rocking of the handle lever 34 relative to the front wall 13 causes the trip dog 47 to rock the selector bell crank 50 to open the valve 29 for hydraulically energizing the motor 17 to drive the bender plate 14 in a clockwise direction. Rocking of the handle lever 34 inwardly from 4 a neutral position toward the front wall 13 causes the trip dog 48 to rock the selector bell crank to open the valve 29 for hydraulically energizing the motor 17 to drive the bender plate 14 in a clockwise direction. Since trip dogs 47 and 48 normally maintain their thrust connection with the selector bell crank 50 throughout the full range of rocking of the handle lever 34, to both sides of the neutral position a full range of speed control is attainable through manipulation of the handle lever, smoothly transitionally from. neutral through slow or pickup speed to fast speed in either direction under manual control. This enables high speed quantity production by enabling quick acceleration and fast reversal, and enables opposite bends to be made in a workpiece by rocking the handle lever first to one'side of neutral and then to the opposite side of neutral. At any time the .valve can be quickly manually returned to closed position. So-called inching in either direction is facilitated by the slow speed capability of the control means, and this is advantageous for experimental work and when setting up full production.

To controlthe respective opposite opening limits of the valve 29 positively and accurately, respective stops comprising screws 61 are mounted to oppose the opposite ends of the cross arm 45 and limit the valve-opening rocking movements thereof. For this purpose, the screws are adjustably mounted in a cross bar 61a which is fixed to the bracket 44 in suitably spaced parallel relation to the cross arm 45.

For accurate duplication of workpieces and more particularly bends in successive workpieces, motor driven means are provided for automatically disengaging the selector 33, and more particularly the respective trip dogs 47 and 48 within any desired predetermined interval of driving motor travel. To this end, means comprising a linearly movably mounted combination index and abutment 62 (FIGS. 2, 4 and 8) are driven by the motor 17 to actuate, selectively, normally inactive selector tripping mechanism including a movable stop-carrying gaging device 63 (FIGS. 1, 5, 7 and 8).

In an efiicient arrangement, the combination index and abutment means 62 comprise a generally L-shaped block member 64 which is constructed and arranged to provide an upwardly extending portion 65 and a horizontally extending lower abutment portion 66 defining therebetween a re-entrant angle within which is received a horizontally extending run of an endless flexible drive member 67 comprising a sprocket chain which is trained over a pair of idlers 68 (FIG. 2) and a driving sprocket 69 which is corotatively keyed to the motor shaft 15 so that a direct motor drive of the chain is effected. Mounting of the idlers 68 is adjacent to the opposite inner sides of the cabinet front wall 13 adjacently under the table 11 whereby a long horizontal run of the chain 67 extends adjacently parallel to the inside of the front wall 13. As the motor drives the bender plate 14 counterclockwise, the motor concurrently drives the chain 67 to move the front run thereof linearly to the right. Likewise, clockwise driving of the plate 14 by the motor concurrently effects linear movement of the front run of the chain toward the left. In these linear movements of the front run of the chain, the index and abutment means 62 are carried linearly therewith.

Attachment of the member 64 to the chain 67 is conveniently effected by means of an angle plate 70' (FIGS. 4 and 8) secured as by means of a screw 71 to the inner face of the upstanding portion 65 and having a horizontal flange 72 of the same dimensions as and substituted for one of the upper side link plates of the chain. Two of the link connecting pins of the chain, to which the link flange 72 is connected are provided with extensions 73 extending downwardly from the chain through respective holes 74 in the abutment portion 66 for thereby firmly connecting the member 64 for linear movement with the chain and against displacement even though substantial thrust pressure may be exerted by or against the abutment portion 66.

Linear positions of the abutment 66 are usefully observable through the medium of a generally L-shaped index pointer 75 which is secured to the upper part of the front face of the block portion 65 and extends outwardly through an elongated horizontal slot 77 in the front wall 13, with an upwardly extending index portion spaced a limited distance from the outer face of the wall. Extending along the upper edge of the slot 77 behind the pointer 75 on the outer face of the front wall 13 is an elongated calibrated scale panel 78 longitudinally slidably adjustably supported by upper and lower complementary angle bracket strips 79, By having the scale calibrated by bend degrees, and adjustable, quick reference is afforded for setting the control mechanism to attain desired predeterminable and resettable bending results.

For operation of the gaging device 63 by the abutment 66, respective adjustable stops 80 are mounted on an elongated gage bar 81 extending in suitable spaced parallel relation below the front linear run of the index and abutment driving chain 67. For this purpose, the bar 81 is mounted for both limited longitudinal reciprocalmovement and full rotary indexing movement, with one end portion of the bar, herein the left end portion being journaled through a pillow block 82 mounted on the inside of the front wall 13 and slidably mounting a bushing hearing 83 about the bar 81 and held co-reciprocally therewith by means of respective Washers 84 retained in annular grooves 85 in the bar.

Normally the bar 81 is held yieldably in a neutral longitudinal position by means of coiled compression neutralizing and biasing springs 87 having respective ends engaging thrust washers 88 freely abutting the sides of the pillow block 82. One of the springs 87 has its opposite end in abutment with a retaining washer 89 seated in an annular groove 90 adjacent to the extremity of the bar. The opposite spring 87 has its other end thrusting against a shoulder 91 on a larger diameter portion of the bar. Through this arrangement, movement of the bar 81 reciproca bly in either direction is resisted by the respective return spring 87 which acts immediately when the bar is released from shifting pressure to return the bar to its neutral position.

For adjustably mounting the stops 80 to attain a large range of repetitive bending results, the larger diameter portion of the bar 81 extends throughout at least the length of the scale 78, and which extends throughout the length of travel of the index pointer 75 as effected by the opposite limits of oscillation travel of the hydraulic motor 17. For mounting the stops 80 adjustably, the stop-carrying larger diameter portion of the bar is provided with a multi-faced cross section, herein hexagonal, affording fixed longitudinally extending faces 92. Adjacent to one end of the faces 92 a longitudinally slidable stop-carrying disk 93 is mounted having a radially extending set of the stops 80 projecting therefrom in respective alignment with five of the faces 92 (FIG. 8). At suitable selected intervals along the remainder of the multi-faced stop-carrying portion of the gage bar are mounted as many as desired of single stop carriers 94 and 95. For ease in placing, replacing, and adjusting the stop carriers 94 and 95 they are of generally C-shape having bar-engaging faces complementary to any four of the bar faces 92. By having the respective stop 80 on each of the carriers 95 mounted on a lateral boss flange 97, substantially as shown in FIGURES 5 and 6, fractional degree bend differentials are attainable on workpieces by mounting the carriers 95 byadjacent relatively circumferentially offset pairs with the respective stops 80 in adjusted relatively overlapping relation.

To enable quick, simple adjustment and positive retention of the stop carriers in adjusted position, the stops 80 are desirably in the form of socket headed set screws in which the heads provide the stops and the shanks are threaded radially into and through the respective carriers to engage lockingly against the opposed shaft faces 92. For ready access to the stops to effect attachment and adjustment of the carriers for desired bend settings, the front wall 13 of the cabinet is provided with a suitable horizontal access opening or slot 98 (FIGS. 1 and 5).

Through the arrangement described, adjusted settings of the stops are adapted to be made for a variety of different bends to be effected successively on a workpiece. The stops aligned with each of the gage bar faces 92 are adjusted longitudinally thereof for a particular bend and then for each successive bend the bar 81 is rotated to bring into alignment with the abutment 66 that particular pair of longitudinally spaced abutments 80 which will effect the desired gaged valve-closing actuation of the stop carrying device 63. In the arrangement shown, settings for five different bends on each workpiece can be effected by selectively indexing five of the faces 92 into working alignment with the stop 66, the sixth face being free from stops to enable selective free manual operation to the opposite limits of motor travel.

For manual rotary indexing of the bar 81 to select the various stop settings, the righthand end portion of the bar is journaled through a combination pillow block and click detent assembly 99 mounted along the inner side of the front wall 13, with the righthand extremity portion of the shaft extending outwardly at that side of the cabinet 12 and carrying a hand wheel 100 by which the bar can be manually rotatably adjusted. 'In the assembly 99 a pair of complementary half pillow blocks 101 are mounted in side by-side spaced relation, with the bar 81 slidably journaled through the inner of the pillow blocks and having a smaller diameter portion 102 extending on through the outer of the pillow blocks 101 and through a bushing bearing 103. About the shaft portion 102 between the pillow blocks 101 is a click detent disk 104 through which the shaft freely slides longitudinally but is connected by a key 105 corotatively with the shaft. At six spaced intervals aligned with the six faces 92, the disk 104 has therethrough respective detent socket bores 107 within which are torque releasably engageable one or more sets of opposed larger diameter ball detents 108 urged toward the disk in a manner to avoid binding of the disk with the pillow blocks by respective substantially thrust equalizing biasing means comprising compression springs 109. Through this arrangement, selective alignment of the sets of stops with the abutment 66 is readily effected by turning the bar 81 by means of the hand wheel 100. Sensory indication by feel and possibly also by sound afforded by the detent mechanism indicates attainment of any desired adjusted position as the gage bar 81 is rotated. Through the detent disk 104, the detents 108 retain the bar in any desired rotary adjustment.

Respective abutment-thrust effected reciprocal movements of the gage bar 81 disconnect the selector 33, by tripping whichever one of the trip dogs 47 and 48 is selectively in valve-opening thrusting coaction with the bell crank 50. Accordingly, a motion-transmitting linkage is provided from the gage bar 81 to the selector 33, comprising a bell crank member 110 (FIGS. 5, 7 and 8) which is pivotally connected by means of a pin 111 to a supporting bracket 112 mounted operatively adjacent to the bar 81 inside the cabinet front wall 13, desirably adjacent to the inner of the pillow blocks 101. Respective opposite reciprocal movements of the bar 81 are converted into rocking movements of the transmission bell crank 110 by connection of a yoke arm 113 of the bell crank to the bar by means of opposed follower pins 114 engaging in an annular groove 115 in the bar. A second arm 117 of the transmission bell crank has pivotally connected thereto one end of a link 118 the opposite end of which is pivotally connected to a driving arm 119 (FIG. 3) fixedly attached to the shaft 51 of the selector assembly. Also fixedly attached to the shaft 51 is a T-shaped tripper comprising a rocker arm 120 having thereon a crosshead 121 which is of a length slightly less than the normal distance between the trip dogs 47 and 48. In its normal, neutral position, the tripper 121 has its opposite ends 122 and 123 respectively free and clear of the confronting inside edges of the trip dogs 47 and 48. Through this arrangement, both of the trip dogs 47 and 48, remain normally in thrusting relation to their respective thrust shoulder pins 53 on the selector bell crank 50. Tripping release of either of the trip dogs 47 and 48 from such thrusting operational relation to its respective shoulder pin is effected by lateral thrust of the tripper 121 thereagainst, comprising tripping thrust against the trip dog 47 when the gage bar 81 is shifted toward the right, and tripping thrust against the trip dog 48 when the gage bar 81 is shfted to the left. In either instance, promptly upon disengagement of the respective trip dog from its shoulder means pin 53, and thus release of the selector bell crank 50, the relevant return spring 30 or 31 moves the valve 29 to its circuit-closing position and stops the motor 17. As a result, by suitable setting of the gaging stops 80 on the gage bar 81 automatic motor shutoff is attained at any gaged interval desired. Nevertheless, stopping or reversal of the motor can be efiected at will by the operator before any particular gaging stop is reached, simply by releasing the handle lever 34 to stop the motor or by actuating the handle lever in reverse to reverse the motor.

In operation, control of the motor 17 and thereby operation of the bender through the plate 14 may be entirely through the operating handle lever 34. During such entirely manually controlled operation, the index pointer 75 and the scale 78 may be, if desired, used as a guide by the operator to determine the degree of bend. However, accurate duplication of respective bends in successive workpieces, as for production runs, is efiected by setting of the gage stops 80 along the supporting portion of the gage bar 81 and the motor will be automatically stopped by closing of the motor circuit controlling valve 29 by tripping of the responsible trip dogs 47 and 48 as each bend is completed. Several difierent bends, of any of a very large number of respective full and fractional bend degrees, may be accomplished according to a preset schedule by successively turning the gage bar 81 to orient the appropriate gage stop with the traveling abutment 66. Further, resetting of the gaging device 63 to repeat a particular bending schedule is easily effected by resetting the gage stops with the aid of the calibrated scale and index.

It will be understood that variations and modifications may be effected without departing from the spirit and scope of the novel concepts of this invention.

We claim:

1. In control means for a tool-driving hydraulic motor having a pressure fluid circuit including a normally closed control valve:

means operative for selectively opening said valve to connect said circuit drivingly with the motor and including a trip dog;

normally inactive trip mechanism associated with said dog and including a movable stop-carrying device and a tripper operatively movably connected thereto; and linearly movably mounted abutment means driven by the motor and operative within a predetermined interval of motor travel to abut a stop on said device to move said device and through it to move said tripper to deactivate said dog, whereby said valve closes and disconnects said circuit to stop the motor.

2. Control means as defined in claim 1, in which said first mentioned means comprise a bell crank connected to the valve, a rockably mounted member spaced from said bell crank, and said trip dog comprises a bar pivotally connected at one end to said member and having a connection with the bell crank which is separable by action of the tripper against the trip dog.

3. Control means as defined in claim 2, comprising two trip dogs each of which comprises a bar pivotally connected to said member, said bell crank having three arms two of which are aligned in oppositely projecting relation and a third of which projects between the two arms and is connected to the motor, said trip dog bars respectively disconnectibly engaging said two arms, and said tripper comprising a bar mounted between and normally out of engagement with both of said bars and being selectively movable into tripping engagement with either of said trip dogs to disconnect it from the bell crank while the remaining trip dog remains in engagement with its arm of the bell crank.

4. Control means as defined in claim 2, including adjustable stop means controlling the extent of rocking movement of said member.

5. Control means as defined in claim 1, in which said abutment means comprise: a linearly guided member, an abutment block mounted on and carried reciprocably by said member, and an indexing pointer mounted on said block.

6. Control means as defined in claim 5, including an elongated calibrated scale longitudinally adjustably mounted in association with said pointer.

7. Control means as defined in claim 1, in which said motor is of the rotary actuator type having a tool driving shaft, a sprocket chain mounted on said shaft, and said member comprises a sprocket chain trained over said sprocket.

8. Control means as defined in claim 1, in which said stop carrying device comprises a bar carrying stops thereon, and means reciprocably mounting said bar operatively adjacent to said index and abutment means.

9. Control means as defined in claim 8, in which said bar is rotatable for indexing selected stops in the path of said abutment means.

10. Control means as defined in claim 9, including selective detent means for maintaining the bar in its indexed positions.

11. Control means as defined in claim 8, in which a plurality of stops are mounted on said bar and are -ad justa'ble selectively longitudinally along said bar.

12. Control means as defined in claim 8, including a link, means connecting said link to reciprocate in a direction angular to the axis of said bar responsive to reciprocations of the bar and connected to said tripper to eflect dog tripping actuation thereof responsive to movements of the link effected by the bar.

13. Control means as defined in claim 1, and wherein said motor is of the oscillating type and said control valve is operable from its closed position to open said circuit to actuate the motor in either of its oscillating directions selectively, said means for selectively opening the valve comprising a selector having two similar trip dogs in the form of elongated bars pivotally attached to opposite ends of an intermediately rockably mounted arm and the opposite ends of the trip dog bars releasably engaging respective oppositely extending arms of a threearm rockably mounted bell crank having a third intermediate arm operatively connected to said valve, a manual operating lever and a linkage connecting said operating lever to said rockably mounted arm so that when said operating lever is moved in one direction one of said dogs moves said bell crank to open the valve for operation of the motor in one of its oscillatory directions and when the operating lever is moved in the opposite direction the other of said dogs rocks the bell crank to open the valve for driving the motor in the opposite oscillatory direction, said stop carrying device comprising a reciprocably and rotatably mounted bar having a plurality of adjustably mounted stops thereon, said tripper comprising a thrust member rockably mounted between said dogs and normally out of contact with both of the dogs, a linkage connecting said tripper with said bar to translate reciprocal movements of the bar into respectively opposite rocking movements of said tripper for selectively disengaging said dogs from said bell crank, a sprocket reciprocably driven by said motor, a sprocket chain trained over said sprocket and having an elongated run parallel and adjacent to said reciprocal bar, said abutment means being mounted on said elongated run of the chain between selected stops to abut said stops respectively at the ends of predetermined intervals of motor travel in opposite directions for effecting actuation of the tripper to trip the respective dogs to stop the motor, index means associated with said abutment means on said run of the chain, and an adjustable calibrated scale extending parallel to said elongated run of the chain and cooperative with said index means for visual determination of adjustments of said stops on said bar.

14. In control means of the character described, a selector comprising:

a supporting structure;

a cross arm intermediately pivotally mounted on said supporting structure;

respective spaced substantially coextensive trip dogs pivotally connected to the opposite end portions of said arm and having free ends which project away from said arm;

a three-arm bell crank pivotally mounted on said supporting structure and having a pair of oppositely extending arms each of which has thrust shoulder means thereon engageable by a thrust shoulder on the free end of a respective one of said arms, and a third arm having means for connecting it to a control member;

means for rocking said cross arm in either direction to move said dogs selectively for correspondingly rocking said bell crank;

and a tripper mounted between said dogs normally out of contact therewith and operative selectively to disengage the selected dog thrust shoulder from the thrust shoulder means of its associated arm of the bell crank.

15. Control means as defined in claim 14, including a pair of adjustable stops respectively opposing the respective opposite end portions of said cross arm in spaced relation to limit the respective opposite rocking movements thereof.

16. In control means of the character described:

an elongated gage bar;

means mounting said bar for reciprocal movements;

a substantial intermediate length of the bar being provided for mounting thereon of respective stop members;

a plurality of stop members;

means selectively securing said stop members adjustably along said portion of the bar for respective engagement by a bar actuating abutment;

and means connected to the bar for translating reciprocal movements thereof into mechanism controlling movements.

17. Control means as defined in claim 16, in which said portion of the bar is of plural sided transverse cross section, and said stops include carriers having bar engaging faces complementary to the sides of said portion and being adapted to be slidably moved along said section for adjustment, and means for securing the carriers in selected positions of adjustment.

18. Control means as defined in claim 17, in which at least one of said stop carriers is of full annular form to remain on said portion of the bar, and others of the stop carriers are of generally C-shape enabling them to be readily removed and placed on said portion of the bar.

19. Control means as defined in claim 16, in which said bar is also rotatably indexable, and means for pressure releasably maintaining the bar in rotatably indexed relative positions of adjustment.

.20. Control means as defined in claim 16, including means for normally biasing said bar into a neutral position from which it is movable in either axial direction in opposition to said biasing means and to which the biasing means normally returns the bar.

21. Control means as defined in claim 16, in combination with a bending machine including a table mounting bending mechanism comprising an oscillatable tool plate carried on a vertical shaft, an oscillating hydraulic motor for driving said shaft and having operating hydraulic circuitry connected therewith including a normally closed control valve, said mechanism being connected with said control valve and including manual actuating means and a selector which is connected with said bar to be disabled by actuation of said bar reciprocably, an endless flexible driving member, means connecting said driving member to be driven in respective opposite directions in oscillations of said shaft, combination indexing and abutment means carried by said member including an abutment aligned with said stops and an indexing pointer movable therewith, and a scale mounted for movement therealong of said pointer and calibrated by degrees for facilitating adjustment of said stops to secure predetermined bending results in the operation of the bender.

22. A power bending machine comprising:

a supporting structure having an upper work table area;

bending means on said table area including a bending tool mounting plate;

an oscillating spindle extending through said table area and corotationally supporting said plate;

and a rotary vane hydraulic actuator motor below said table area having a wingshaft selectively oscillatably motivated by a constant volume hydraulic pressure supply and which wingshaft is coaxial with and is functionally integral with and directly drives said spindle whereby to attain constant angular spindle velocity with full bending torque power in each oscillatory direction.

References Cited UNITED STATES PATENTS 1,084,707 1/1914 Nazel et al. 72453 1,217,488 2/1917 Myers 72'--30 3,339,397 9/1967 Heimel 72453 3,344,630 10/1967 Lauck 722 ROBERT D. GREFE, Primary Examiner.

US. Cl. X.R. 7226, 30, 32, 453 

